Fuel heater for internalcombustion engines



3mm: [1H Krus chke,

n A 4 V m m A A V Filed D80. 23, 1947 i JIIIIAIIIII II G H KRUSCHKE FUEL HEATER FOR INTERNAL-COMBUSTION ENGINES July 11, 1950 Patented July 11, 1950 UNITED STATES PATENT OFFICE FUEL HEATER FOR INTERNAL- COMBUSTION ENGINES 2 Claims.

This invention relates to electrical fuel heaters for internal combustion engines, and one object of the invention is to provide novel and improved means for heating the fuel in a conventional carbureter to ensure a quick starting of the engine in very cold climates or very cold weather.

Another object of the invention is to provide means of this character which may be heated by current from a conventional battery to heat the fuel before starting the motor, and which is simple of construction and efficient for its intended purpose.

Still another object of the invention is to provide a fuel heater of unitary type which can be readily applied to any conventional type of carbureter at a comparatively low cost, and which is durable and safe in operation and ensures vaporization of the initial changes of fuel for starting with a minimum expenditure of electric current.

The invention consists of the novel features of construction, combination and arrangement of parts, hereinafter more fully described and claimed and shown in the accompanying drawing, in which:

Fig. 1 is a perspective view of a carbureter to which the heater is applied, with a portion of its fuel chamber broken away to show the heater element mounted therein, and showing also the arrangement of the heater in a battery circuit.

Fig. 2 is a view in side elevation of the heater removed from the carbureter.

Fig. 3 is a vertical longitudinal section through a major portion of the heater on an enlarged scale.

Figs. 4, 5 and 6 are detail sections taken on line 44 of Fig. 2 and on lines 55 and 66 of Fig. 3.

Referring now more particularly to the drawing, wherein like reference numerals represent corresponding parts throughout the several views, 1 represents a conventional type of carbureter having a fuel holding float chamber or bowl 2. 3 designates generally my improved heater applied thereto, and 4 designates generally an electrical heating circuit in which the heater is arranged. The carbureter shown for purpose of exemplification is provided with a cover 5 secured thereto by bolts or screws 6.

The heater 3 comprises a tubular stem or upright 1 of metal carrying at its lower end a heater casing or envelope 8 of electrical and heat-conducting metal which is horizontally disposed and extends laterally from the stem. This casing or envelope is preferably in the form of an elongated hollow, fiat body sealed at its outer end 9 and formed at its inner end with a nipple l receiving the lower end of the stem 1 and to which the stem is brazed or otherwise firmly and sealingly secured. In the stem 1 is a body or tube ll of electrical insulating material, and in the casing 8 is a body or tube l2 of insulating material.

Extending downward through the stem 1 and insulated by the material ll therefrom is a feed conductor l3, and arranged within the casing 8 and enclosed between its ends by the insulating material i2 is a fiat heating coil M of Nichrome steel or other suitable material. The lower end of the conductor [3 is joined within the inner end of the casing to the inner end of the coil, as shown at It, while the opposite or outer end of the coil is secured to the sealed outer end 9 of the casing, which constitutes a, ground. This end 9 of the casing is preferably formed by flattening its upper and lower walls and brazing the same together and to the outer end of the coil, but other ways of sealing the casing at this end and securing the coil thereto may be employed.

The heater may be applied to the carbureter in the manner shown, as, for example, by drilling a hole IS in the cover 5 to receive the stem 1 which may be frictionally held in place or brazed, welded or otherwise secured to the cover. The stem is arranged so as to project above the cover and down into the bowl 2 so that the heating unit comprising the casing 8 and coil M will be disposed below the fioat and immersed in the fuel contained in the bowl, whereby the heat from the coil will be distributed to the casing and lower end of the stem to heat the fuel when current is being supplied to the coil.

The electric circuit 4 includes a battery l6, conductors IT and I8 connected with the poles thereof, a switch 9 for closing and opening the circuit, and an indicator 20 for indicating whether or not current is flowing through the heating element. Conductor fl is connected to the feed conductor I3 which supplies current to the coil when the circuit is closed, the circuit being completed by grounding the stem 1 to the carbureter. To ensure a good grounding, the stem 1 may be connected to one of the screws 6 by a ground connection 2!. In the use of the heater on an automobile, or like vehicle, the switch If! and indicator 20 may be mounted on the instrument board or panel so as to be conveniently operated and viewed. A safety fuse 22 may be provided in the switch line, if desired.

The operation of the device will be readily understood. In cold climates or cold weather the fuel may be heated to supply initial charges to the motor so that the motor may be quickly started. The switch is closed only for the length of time required for the purpose, which is short, so that the use of the batter current for this purpose is economized and waste of fuel also prevented. As the device is only in use at this time there is no drain on the battery. The device is so constructed that it will operate efiiciently on current from a 6-volt battery. 7

By constructing the heater casing as a unit independently of the stem and brazing or otherwise permanently connecting these parts together, a leak-proof heater is provided which may be made of light materials, but which is strong and durable and avoids the expense and complexity of using complex fittings to join them, which fittings are liable to cause leakage at the joint or to become otherwise troublesome. At the same time this construction permits of the formation of casings of different sizes, as required, and the use of themwith stems of a given (the same) size, as the casing is not limited in size by the diameter of a stem, as it would be if formed from an extended part of the stem itself. By the use of stems of a given size, applicable to casings varying in size, the necessity of boring holes of different sizes in carburetor casings to receive the stems is avoided, thus simplifying the work of installing heaters in different sizes or types of carburetors. Further, m construction of heater casing adapts the casing to be formed either from out and folded flat stock or from flattened tubular stock, brazed or welded at the joints thereof and to the stern, and the use of an elongated, comparatively wide and fiat casing, with a heating coil of like shape, provides a heater which occupies a minimum amount of space vertically while having a large extent of heating area horizontally, by which the fuel may be more quickly and uniformly heated. In my construction the electric conductor connected with the coil at its end remote from the stem is permanently brazed or welded to the brazed or welded parts of the heater casing at that end, instead of being secured to a screw or other fastening member, and consequently it cannot become loose and cause trouble.

In addition to the advantages above stated, my improved heater reduces the time period the starteris used, thus saving battery current, prevents fiooding and dilution of fuel and washing away of lubricant, raises the specific gravity of the fuel to and above normal for a desirable pe- The usual opening in the carbureter top or cover, normally closed by a plug 23, may be provided for priming the carburetor with fuel when necessary.

Having thus described my invention, I claim:

1. An electrical fuel heater of the character described comprising an elongated, flat and comparatively wide hollow casing of electric conducting and heat-transmitting material and of comparatively shallow depth, said casing being formed from an initially flat tube having its walls at one end brought together and brazed to unite them and hermeticall seal the casing at such end and having its walls at its opposite end united and shaped to form a nipple integral therewith, a fiat heating coil arranged in said casing and clamped and rigidly secured at one end between the walls of the first-named end of the casing, a hollow stem of conducting material fitted and rigidly secured at one end in the nipple at the other end of the casing, and an electric conductor extending through the stem and connected to the other end of the coil.

2. A fuel heater comprising an elongated, comparatively wide and substantially fiat casing of electric conducting heat-transmitting material formedfrom a correspondingly shaped tubular body having its walls at one end flattened and brought together and rigidly united so as to hermetically seal the casing at such end, and having its walls at its opposite end constructed to provide a nipple forming a component part of the casing, a hollow stem formed independently of the casing and fitted and rigidly secured at one end in said nipple, a heating coil disposed in the casing with its body portion insulated therefrom and with one of its ends fixedly held between and conductively connected with the rigidly connected fiattened walls at the sealed end of the casing, and a conductor extending through the stem and connected to the opposite end of the coil.

GUSTAV H. KRUSCHKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

